The invention relates to a toilet flush tank mechanism, and, more particularly, to a selectively bouyant float securable to the flush tank outlet valve adapted for permitting a dual flush system.
Conventional flush-tank toilets in homes and apartments are designed to use a standard volume of water which is considered necessary to flush the toilet bowl satisfactorily under maximum requirement conditions. Often less than maximum water volume can satisfactorily flush the toilet. Accordingly, one way to save water which is so wastefully flushed through toilets is to provide a selective flushing system which utilizes a full flush cycle for solid wastes and a partial flush for liquid wastes.
It may also be seen that in circumstances wherein a shortage of water exists or where it is necessary to use a minimum of water during flushing of a toilet, such as in droughts or when the toilet is connected to a cesspool system of sewerage, it is advantageous to provide dual flushing systems. Apparatus therein designed to provide dual flushing systems for flush-tank toilets may include multiple outlet ports, devices actuated by the fall of a separate float which exerts a force on the outlet valve, or devices actuated by the fall of the conventional float which controlls the inlet means and which by falling exerts a force on the outlet valve.
There are numerous disadvantages to these prior art devices. Some of the aforesaid mechanisms require more than one exterior flushing handle, others have multiple levers, still others employ cams and locking devices. Many of such mechanisms are unreliable in every day operations. Moreoever most of the aforesaid designs are costly and require considerable work, skill and tools for installation. It has also been found that such devices are often hard to operate due to poor leverage characteristics of the actuating mechanism thereof and multiple exterior actuating handle arrangements. Also such devices often include parts which are arranged in a manner wherein lateral forces are exerted on cooperating parts thereof in a manner to cause poor seating of the float means for stopping the flow of water at the termination of flushing cycle or binding of the actuating lever during movement thereof. A further problem has been the wear factor between moving parts which results in poor operation and readjustment of the relative positions of the cooperating parts of the flush tank.
It would be an advantage therefore to provide an improved dual-flush mechanism which fits any ordinary flush-tank toilet and overcomes the problems of the prior art. The apparatus of the present invention is designed for just such a purpose and includes a single open ended float housing directly securable to a commode flush valve and having selectively regulatable venting ports for controlling float weight and bouyancy by the water-air ratio therein. In this manner, additional levers and/or latches and other flush tank apparatus is not necessary to effect a dual-flush system. Similarly, the effective cost of such a device is drastically lowered as is the complexity of installation.